Multi-speed transmission

ABSTRACT

A multiple speed transmission includes an input member, an output member, a plurality of planetary gearsets, a plurality of interconnecting members and a plurality of torque-transmitting mechanisms. The plurality of planetary gear sets includes first, second and third members. The input member is continuously interconnected with at least one member of one of the plurality of planetary gear sets, and the output member is continuously interconnected with another member of one of the plurality of planetary gear sets. At least eight forward speeds and one reverse speed are achieved by the selective engagement of the five torque-transmitting mechanisms.

RELATED APPLICATIONS

The present application is a divisional application of U.S. patentapplication Ser. No. 14/457,592, filed Aug. 12, 2014, the disclosure ofwhich is hereby incorporated by reference.

FIELD OF THE DISCLOSURE

The present disclosure relates to a multiple speed transmission, and inparticular to a multiple speed transmission capable of achieving eightor more speeds.

BACKGROUND

Multiple speed transmissions use a number of friction clutches orbrakes, planetary gearsets, shafts, and other elements to achieve aplurality of gear or speed ratios. The architecture, i.e., packaging orlayout of the aforementioned elements, is determined based on cost,size, packaging constraints, and desired ratios. There is a need for newarchitectural designs of multiple speed transmissions for achievingdifferent ratios with improved performance, cost, efficiency,responsiveness, and packaging.

SUMMARY

In one embodiment of the present disclosure, a multiple speedtransmission includes an input member; an output member; first, second,third and fourth planetary gearsets each having first, second and thirdmembers; a plurality of interconnecting members each connected betweenat least one of the first, second, third, and fourth planetary gearsetsand at least another of the first, second, third, and fourth planetarygearsets; a first torque-transmitting mechanism selectively engageableto interconnect the first member of the first planetary gearset and thefirst member of the second planetary gearset with a stationary member; asecond torque-transmitting mechanism selectively engageable tointerconnect the third member of the first planetary gearset with thestationary member; a third torque-transmitting mechanism selectivelyengageable to interconnect the second member of the second planetarygearset with the first member of the fourth planetary gearset; a fourthtorque-transmitting mechanism selectively engageable to interconnect thethird member of the second planetary gearset and the first member of thethird planetary gearset with the first member of the fourth planetarygearset; and a fifth torque-transmitting mechanism selectivelyengageable to interconnect the third member of the third planetarygearset with the first member of the fourth planetary gearset; whereinthe torque transmitting mechanisms are selectively engageable incombinations of at least three to establish at least eight forward speedratios and at least one reverse speed ratio between the input member andthe output member.

In one example of this embodiment, the input member is continuouslyinterconnected with the second member of the second planetary gearsetand the output member is continuously interconnected with the secondmember of the fourth planetary gearset. In a second example, theplurality of interconnecting members includes a first interconnectingmember continuously interconnecting the first member of the firstplanetary gearset with the first member of the second planetary gearset.In a third example, the plurality of interconnecting members includes asecond interconnecting member continuously interconnecting the secondmember of the first planetary gearset with the second member of thethird planetary gearset and the third member of the fourth planetarygearset.

In a fourth example of this embodiment, the plurality of interconnectingmembers includes a third interconnecting member continuouslyinterconnecting the third member of the second planetary gearset withthe first member of the third planetary gearset. In a fifth example, thefirst, second, and third members of the first, second, third, and fourthplanetary gearsets are each at least one of a sun gear, a ring gear, anda carrier member. In a sixth example, the first members are sun gears,the second members are carrier members, and the third members are ringgears. In a seventh example, each of the plurality of interconnectingmembers are rotationally fixed between at least one of the first,second, third, and fourth planetary gearsets and at least another of thefirst, second, third, and fourth planetary gearsets.

In another embodiment, a multiple speed transmission includes an inputmember; an output member; first, second, third and fourth planetarygearsets each having a sun gear, a carrier member, and a ring gear,wherein the input member and the output member are each interconnectedto at least one of the first, second, third, and fourth planetarygearsets; a first torque-transmitting mechanism selectively engageableto interconnect the sun gear of the first planetary gearset and the sungear of the second planetary gearset with a stationary member; a secondtorque-transmitting mechanism selectively engageable to interconnect thering gear of the first planetary gearset with the stationary member; athird torque-transmitting mechanism selectively engageable tointerconnect the carrier member of the second planetary gearset with thesun gear of the fourth planetary gearset; a fourth torque-transmittingmechanism selectively engageable to interconnect the ring gear of thesecond planetary gearset and the sun gear of the third planetary gearsetwith the sun gear of the fourth planetary gearset; and a fifthtorque-transmitting mechanism selectively engageable to interconnect thering gear of the third planetary gearset with the sun gear of the fourthplanetary gearset; wherein the torque transmitting mechanisms areselectively engageable in combinations of at least three to establish atleast eight forward speed ratios and at least one reverse speed ratiobetween the input member and the output member.

In one example of this embodiment, a first interconnecting membercontinuously interconnects the sun gear of the first planetary gearsetwith the sun gear of the second planetary gearset. In a second example,a second interconnecting member continuously interconnects the carriermember of the first planetary gearset with the carrier member of thethird planetary gearset and the ring gear of the fourth planetarygearset. In a third example, a third interconnecting member continuouslyinterconnects the ring gear of the second planetary gearset with the sungear of the third planetary gearset. In a fourth example, the inputmember is continuously interconnected with the carrier member of thesecond planetary gearset, and the output member is continuouslyinterconnected with the carrier member of the fourth planetary gearset.

In a different embodiment, a multiple speed transmission includes aninput member; an output member; first, second, third and fourthplanetary gearsets each having first, second and third members; aplurality of interconnecting members each connected between at least oneof the first, second, third, and fourth planetary gearsets and at leastanother of the first, second, third, and fourth planetary gearsets; afirst torque-transmitting mechanism selectively engageable tointerconnect the first member of the first planetary gearset and thefirst member of the second planetary gearset with a stationary member; asecond torque-transmitting mechanism selectively engageable tointerconnect the third member of the first planetary gearset with thestationary member; a third torque-transmitting mechanism selectivelyengageable to interconnect the second member of the second planetarygearset with the first member of the third planetary gearset and thefirst member of the fourth planetary gearset; a fifthtorque-transmitting mechanism selectively engageable to interconnect thethird member of the second planetary gearset and the third member of thethird planetary gearset; and a fourth torque-transmitting mechanismselectively engageable to interconnect the third member of the secondplanetary gearset with the first member of the third planetary gearsetand the first member of the fourth planetary gearset; wherein the torquetransmitting mechanisms are selectively engageable in combinations of atleast three to establish at least eight forward speed ratios and atleast one reverse speed ratio between the input member and the outputmember.

In one example of this embodiment, the input member is continuouslyinterconnected with the second member of the second planetary gearsetand the output member is continuously interconnected with the secondmember of the fourth planetary gearset. In a second example, theplurality of interconnecting members includes a first interconnectingmember continuously interconnecting the first member of the firstplanetary gearset with the first member of the second planetary gearset.In a third example, the plurality of interconnecting members includes asecond interconnecting member continuously interconnecting the secondmember of the first planetary gearset with the second member of thethird planetary gearset and the third member of the fourth planetarygearset. In a fourth example, the plurality of interconnecting membersincludes a third interconnecting member continuously interconnecting thefirst member of the third planetary gearset with the first member of thefourth planetary gearset.

In a further embodiment of the present disclosure, a multiple speedtransmission includes an input member; an output member; first, second,third and fourth planetary gearsets each having a sun gear, a carriermember, and a ring gear, wherein the input member and the output memberare each interconnected to at least one of the first, second, third, andfourth planetary gearsets; a first torque-transmitting mechanismselectively engageable to interconnect the sun gear of the firstplanetary gearset and the sun gear of the second planetary gearset witha stationary member; a second torque-transmitting mechanism selectivelyengageable to interconnect the ring gear of the first planetary gearsetwith the stationary member; a third torque-transmitting mechanismselectively engageable to interconnect the carrier member of the secondplanetary gearset with the sun gear of the third planetary gearset andthe sun gear of the fourth planetary gearset; a fifthtorque-transmitting mechanism selectively engageable to interconnect thering gear of the second planetary gearset with the ring gear of thethird planetary gearset; and a fourth torque-transmitting mechanismselectively engageable to interconnect the ring gear of the secondplanetary gearset with the sun gear of the third planetary gearset andthe sun gear of the fourth planetary gearset; wherein the torquetransmitting mechanisms are selectively engageable in combinations of atleast three to establish at least eight forward speed ratios and atleast one reverse speed ratio between the input member and the outputmember.

In one example of this embodiment, a first interconnecting membercontinuously interconnects the sun gear of the first planetary gearsetwith the sun gear of the second planetary gearset. In a second example,a second interconnecting member continuously interconnects the carriermember of the first planetary gearset with the carrier member of thethird planetary gearset and the ring gear of the fourth planetarygearset. In a third example, a third interconnecting member continuouslyinterconnects the sun gear of the third planetary gearset with the sungear of the fourth planetary gearset.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned aspects of the present disclosure and the manner ofobtaining them will become more apparent and the disclosure itself willbe better understood by reference to the following description of theembodiments of the disclosure, taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is an exemplary block diagram and schematic view of oneillustrative embodiment of a powered vehicular system;

FIG. 2 is a diagrammatic view of one embodiment of a multiple speedtransmission;

FIG. 3 is a diagrammatic view of another embodiment of a multiple speedtransmission; and

FIG. 4 is a truth table presenting an example of a state of engagementof various torque transmitting mechanisms in each of the availableforward and reverse speeds or gear ratios of the transmissionillustrated in FIGS. 2 and 3.

Corresponding reference numerals are used to indicate correspondingparts throughout the several views.

DETAILED DESCRIPTION

The embodiments of the present disclosure described below are notintended to be exhaustive or to limit the disclosure to the preciseforms disclosed in the following detailed description. Rather, theembodiments are chosen and described so that others skilled in the artmay appreciate and understand the principles and practices of thepresent disclosure.

Referring now to FIG. 1, a block diagram and schematic view of oneillustrative embodiment of a vehicular system 100 having a drive unit102 and transmission 118 is shown. In the illustrated embodiment, thedrive unit 102 may include an internal combustion engine, diesel engine,electric motor, or other power-generating device. The drive unit 102 isconfigured to rotatably drive an output shaft 104 that is coupled to aninput or pump shaft 106 of a conventional torque converter 108. Theinput or pump shaft 106 is coupled to an impeller or pump 110 that isrotatably driven by the output shaft 104 of the drive unit 102. Thetorque converter 108 further includes a turbine 112 that is coupled to aturbine shaft 114, and the turbine shaft 114 is coupled to, or integralwith, a rotatable input shaft 124 of the transmission 118. Thetransmission 118 can also include an internal pump 120 for buildingpressure within different flow circuits (e.g., main circuit, lubecircuit, etc.) of the transmission 118. The pump 120 can be driven by ashaft 116 that is coupled to the output shaft 104 of the drive unit 102.In this arrangement, the drive unit 102 can deliver torque to the shaft116 for driving the pump 120 and building pressure within the differentcircuits of the transmission 118.

The transmission 118 can include a planetary gear system 122 having anumber of automatically selected gears. An output shaft 126 of thetransmission 118 is coupled to or integral with, and rotatably drives, apropeller shaft 128 that is coupled to a conventional universal joint130. The universal joint 130 is coupled to, and rotatably drives, anaxle 132 having wheels 134A and 134B mounted thereto at each end. Theoutput shaft 126 of the transmission 118 drives the wheels 134A and 134Bin a conventional manner via the propeller shaft 128, universal joint130 and axle 132.

A conventional lockup clutch 136 is connected between the pump 110 andthe turbine 112 of the torque converter 108. The operation of the torqueconverter 108 is conventional in that the torque converter 108 isoperable in a so-called “torque converter” mode during certain operatingconditions such as vehicle launch, low speed and certain gear shiftingconditions. In the torque converter mode, the lockup clutch 136 isdisengaged and the pump 110 rotates at the rotational speed of the driveunit output shaft 104 while the turbine 112 is rotatably actuated by thepump 110 through a fluid (not shown) interposed between the pump 110 andthe turbine 112. In this operational mode, torque multiplication occursthrough the fluid coupling such that the turbine shaft 114 is exposed todrive more torque than is being supplied by the drive unit 102, as isknown in the art. The torque converter 108 is alternatively operable ina so-called “lockup” mode during other operating conditions, such aswhen certain gears of the planetary gear system 122 of the transmission118 are engaged. In the lockup mode, the lockup clutch 136 is engagedand the pump 110 is thereby secured directly to the turbine 112 so thatthe drive unit output shaft 104 is directly coupled to the input shaft124 of the transmission 118, as is also known in the art.

The transmission 118 further includes an electro-hydraulic system 138that is fluidly coupled to the planetary gear system 122 via a number,J, of fluid paths, 140 ₁-140 _(J), where J may be any positive integer.The electro-hydraulic system 138 is responsive to control signals toselectively cause fluid to flow through one or more of the fluid paths,140 ₁-140 _(J), to thereby control operation, i.e., engagement anddisengagement, of a plurality of corresponding friction devices in theplanetary gear system 122. The plurality of friction devices mayinclude, but are not limited to, one or more conventional brake devices,one or more torque transmitting devices, and the like. Generally, theoperation, i.e., engagement and disengagement, of the plurality offriction devices is controlled by selectively controlling the frictionapplied by each of the plurality of friction devices, such as bycontrolling fluid pressure to each of the friction devices. In oneexample embodiment, which is not intended to be limiting in any way, theplurality of friction devices include a plurality of brake and torquetransmitting devices in the form of conventional clutches that may eachbe controllably engaged and disengaged via fluid pressure supplied bythe electro-hydraulic system 138. In any case, changing or shiftingbetween the various gears of the transmission 118 is accomplished in aconventional manner by selectively controlling the plurality of frictiondevices via control of fluid pressure within the number of fluid paths140 ₁-140 _(J).

The system 100 further includes a transmission control circuit 142 thatcan include a memory unit 144. The transmission control circuit 142 isillustratively microprocessor-based, and the memory unit 144 generallyincludes instructions stored therein that are executable by a processorof the transmission control circuit 142 to control operation of thetorque converter 108 and operation of the transmission 118, i.e.,shifting between the various gears of the planetary gear system 122. Itwill be understood, however, that this disclosure contemplates otherembodiments in which the transmission control circuit 142 is notmicroprocessor-based, but is configured to control operation of thetorque converter 108 and/or transmission 118 based on one or more setsof hardwired instructions and/or software instructions stored in thememory unit 144.

In the system 100 illustrated in FIG. 1, the torque converter 108 andthe transmission 118 include a number of sensors configured to producesensor signals that are indicative of one or more operating states ofthe torque converter 108 and transmission 118, respectively. Forexample, the torque converter 108 illustratively includes a conventionalspeed sensor 146 that is positioned and configured to produce a speedsignal corresponding to the rotational speed of the pump shaft 106,which is the same rotational speed of the output shaft 104 of the driveunit 102. The speed sensor 146 is electrically connected to a pump speedinput, PS, of the transmission control circuit 142 via a signal path152, and the transmission control circuit 142 is operable to process thespeed signal produced by the speed sensor 146 in a conventional mannerto determine the rotational speed of the pump shaft 106/drive unitoutput shaft 104.

The transmission 118 illustratively includes another conventional speedsensor 148 that is positioned and configured to produce a speed signalcorresponding to the rotational speed of the transmission input shaft124, which is the same rotational speed as the turbine shaft 114. Theinput shaft 124 of the transmission 118 is directly coupled to, orintegral with, the turbine shaft 114, and the speed sensor 148 mayalternatively be positioned and configured to produce a speed signalcorresponding to the rotational speed of the turbine shaft 114. In anycase, the speed sensor 148 is electrically connected to a transmissioninput shaft speed input, TIS, of the transmission control circuit 142via a signal path 154, and the transmission control circuit 142 isoperable to process the speed signal produced by the speed sensor 148 ina conventional manner to determine the rotational speed of the turbineshaft 114/transmission input shaft 124.

The transmission 118 further includes yet another speed sensor 150 thatis positioned and configured to produce a speed signal corresponding tothe rotational speed of the output shaft 126 of the transmission 118.The speed sensor 150 may be conventional, and is electrically connectedto a transmission output shaft speed input, TOS, of the transmissioncontrol circuit 142 via a signal path 156. The transmission controlcircuit 142 is configured to process the speed signal produced by thespeed sensor 150 in a conventional manner to determine the rotationalspeed of the transmission output shaft 126.

In the illustrated embodiment, the transmission 118 further includes oneor more actuators configured to control various operations within thetransmission 118. For example, the electro-hydraulic system 138described herein illustratively includes a number of actuators, e.g.,conventional solenoids or other conventional actuators, that areelectrically connected to a number, J, of control outputs, CP₁-CP_(J),of the transmission control circuit 142 via a corresponding number ofsignal paths 72 ₁-72 _(J), where J may be any positive integer asdescribed above. The actuators within the electro-hydraulic system 138are each responsive to a corresponding one of the control signals,CP₁-CP_(J), produced by the transmission control circuit 142 on one ofthe corresponding signal paths 72 ₁-72 _(J) to control the frictionapplied by each of the plurality of friction devices by controlling thepressure of fluid within one or more corresponding fluid passageway 140₁-140 ₁, and thus control the operation, i.e., engaging and disengaging,of one or more corresponding friction devices, based on informationprovided by the various speed sensors 146, 148, and/or 150.

The friction devices of the planetary gear system 122 are illustrativelycontrolled by hydraulic fluid which is distributed by theelectro-hydraulic system in a conventional manner. For example, theelectro-hydraulic system 138 illustratively includes a conventionalhydraulic positive displacement pump (not shown) which distributes fluidto the one or more friction devices via control of the one or moreactuators within the electro-hydraulic system 138. In this embodiment,the control signals, CP₁-CP_(J), are illustratively analog frictiondevice pressure commands to which the one or more actuators areresponsive to control the hydraulic pressure to the one or morefrictions devices. It will be understood, however, that the frictionapplied by each of the plurality of friction devices may alternativelybe controlled in accordance with other conventional friction devicecontrol structures and techniques, and such other conventional frictiondevice control structures and techniques are contemplated by thisdisclosure. In any case, however, the analog operation of each of thefriction devices is controlled by the control circuit 142 in accordancewith instructions stored in the memory unit 144.

In the illustrated embodiment, the system 100 further includes a driveunit control circuit 160 having an input/output port (I/O) that iselectrically coupled to the drive unit 102 via a number, K, of signalpaths 162, wherein K may be any positive integer. The drive unit controlcircuit 160 may be conventional, and is operable to control and managethe overall operation of the drive unit 102. The drive unit controlcircuit 160 further includes a communication port, COM, which iselectrically connected to a similar communication port, COM, of thetransmission control circuit 142 via a number, L, of signal paths 164,wherein L may be any positive integer. The one or more signal paths 164are typically referred to collectively as a data link. Generally, thedrive unit control circuit 160 and the transmission control circuit 142are operable to share information via the one or more signal paths 164in a conventional manner. In one embodiment, for example, the drive unitcontrol circuit 160 and transmission control circuit 142 are operable toshare information via the one or more signal paths 164 in the form ofone or more messages in accordance with a society of automotiveengineers (SAE) J-1939 communications protocol, although this disclosurecontemplates other embodiments in which the drive unit control circuit160 and the transmission control circuit 142 are operable to shareinformation via the one or more signal paths 164 in accordance with oneor more other conventional communication protocols (e.g., from aconventional databus such as J1587 data bus, J1939 data bus, IESCAN databus, GMLAN, Mercedes PT-CAN).

Referring to FIG. 2, a schematic representation or stick diagramillustrates one embodiment of a multi-speed transmission 200 accordingto the present disclosure. The transmission 200 includes an input shaft202 and an output shaft 204. The input shaft 202 and output shaft 204can be disposed along the same axis or centerline of the transmission200. In another aspect, the different shafts can be disposed alongdifferent axes or centerlines. In a further aspect, the different shaftscan be disposed parallel to one another, but along different axes orcenterlines. Other aspect can be appreciated by one skilled in the art.

The transmission 200 can also include a plurality of planetary gearsets.In the illustrated embodiment of FIG. 2, the transmission 200 includes afirst planetary gearset 206, a second planetary gearset 208, a thirdplanetary gearset 210, and a fourth planetary gearset 212. Eachplanetary gearset can be referred to as a simple or compound planetarygearset. For example, in some aspects, one or more of the plurality ofplanetary gearsets can be formed as an idler planetary gearset, althoughin FIG. 2 each planetary gearset is illustrated as a simple planetarygearset. One or more of the plurality of planetary gearsets can bearranged in different locations within the transmission 200, but forsake of simplicity and in this particular example only, the planetarygearsets are aligned in an axial direction consecutively in sequence(i.e., first, second, third, and fourth between the input and outputshafts).

The transmission 200 may also include a plurality of torque-transmittingor gearshifting mechanisms. For example, one or more of these mechanismscan include a clutch or brake. In one aspect, each of the plurality ofmechanisms is disposed within an outer housing of the transmission 200.In another aspect, however, one or more of the mechanisms may bedisposed outside of the housing. Each of the plurality of mechanisms canbe coupled to one or more of the plurality of planetary gearsets, whichwill be described further below.

In the embodiment of FIG. 2, the transmission 200 can include a firsttorque-transmitting mechanism 258 and a second torque-transmittingmechanism 260 that are configured to function as brakes (e.g., eachtorque-transmitting mechanism is fixedly coupled to the outer housing ofthe transmission 200). These brakes can be configured asshiftable-friction-locked disk brakes, shiftable friction-locked bandbrakes, shiftable form-locking claw or conical brakes, or any other typeof known brake. The transmission 200 can include a thirdtorque-transmitting mechanism 262, a fourth torque-transmittingmechanism 264, and a fifth torque-transmitting mechanism 266 that areconfigured to function as clutches. These can be shiftablefriction-locked multi-disk clutches, shiftable form-locking claw orconical clutches, wet clutches, or any other known form of a clutch.With these five torque-transmitting mechanisms, selective shifting of atleast eight forward gears and at least one reverse gear is possible.

The transmission 200 of FIG. 2 may also include up to eight differentshafts, which is inclusive of the input shaft 202 and output shaft 204.Each of these shafts, designated as a first shaft 222, a second shaft224, a third shaft 226, a fourth shaft 236, a fifth shaft 246, and asixth shaft 248, are configured to be connected to one or more of theplurality of planetary gearsets or plurality of torque-transmittingmechanism between the input shaft 202 and output shaft 204.

In FIG. 2, the first planetary gearset 206 can include a first sun gear214, a first ring gear 216, and a first carrier member 218 thatrotatably supports a set of pinion gears 220. The second planetarygearset 208 can include a second sun gear 228, a second ring gear 230,and a second carrier member 232 that rotatably supports a set of piniongears 234. The third planetary gearset 210 can include a third sun gear238, a third ring gear 240, and a third carrier member 242 thatrotatably supports a set of pinion gears 244. The fourth planetarygearset 212 can include a fourth sun gear 250, a fourth ring gear 252,and a fourth carrier member 254 that rotatably supports a set of piniongears 256.

The transmission 200 is capable of transferring torque from the inputshaft 202 to the output shaft 204 in at least eight forward gears orratios and at least one reverse gear or ratio. Each of the forwardtorque ratios and the reverse torque ratios can be attained by theselective engagement of one or more of the torque-transmittingmechanisms (i.e., torque-transmitting mechanisms 258, 260, 262, 264, and266). Those skilled in the art will readily understand that a differentspeed ratio is associated with each torque ratio. Thus, at least eightforward speed ratios and at least one reverse speed ratio may beattained by transmission 200. An example of the gear ratios that may beobtained using the embodiments of the present disclosure are also shownin FIG. 4. Of course, other gear ratios are achievable depending on thegear diameter, gear tooth count and gear configuration selected.

As for the transmission 200, kinematic coupling of the first planetarygearset 206 is shown in FIG. 2. The first sun gear 214 is coupled to thefirst shaft 222 for common rotation therewith. The first ring gear 216is coupled to the second shaft 224 for common rotation therewith. Firstpinion gears 220 are configured to intermesh with the first sun gear 214and first ring gear 216. First carrier member 218 is coupled for commonrotation with the third shaft 226.

With respect to the second planetary gearset 208, the second sun gear228 is coupled to the first shaft 222 and first sun gear 214 for commonrotation therewith. The second ring gear 230 is coupled to the fourthshaft 236 for common rotation therewith. Second pinion gears 234 areconfigured to intermesh with the second sun gear 228 and second ringgear 230, and the second carrier member 232 is coupled for commonrotation with the input shaft 202.

The third sun gear 238 of the third planetary gearset 210 is coupled tothe fourth shaft 236 as well, and thus is disposed in common rotationwith the second ring gear 230. The third ring gear 240 is coupled to thefifth shaft 246 for common rotation therewith. Third pinion gears 244are configured to intermesh with the third sun gear 238 and third ringgear 240, and the third carrier member 242 is coupled for commonrotation with the third shaft 226. Thus, the third carrier member 242 isdisposed in common rotation with the first carrier member 218 as well.

The kinematic relationship of the fourth planetary gearset 212 is suchthat the fourth sun gear 250 is coupled to the sixth shaft 248 forcommon rotation therewith. The fourth ring gear 252 is coupled to thethird shaft 226 for common rotation therewith. Moreover, the kinematiccoupling of the third shaft 226 and fourth ring gear 252 further couplesthe fourth ring gear 252 to the first carrier member 218 and thirdcarrier member 242 via the third shaft 226. The fourth pinions 256 areconfigured to intermesh with the fourth sun gear 250 and the fourth ringgear 252. The fourth carrier member 254 is coupled to the output shaft204 for common rotation therewith.

With regards to the kinematic coupling of the five torque-transmittingmechanisms to the previously described shafts, the multiple speedtransmission 200 of FIG. 2 provides that the first torque-transmittingmechanism 258 is arranged within the power flow between the first shaft222 and the housing G of the transmission 200. In this manner, the firsttorque-transmitting mechanism 258 is configured to act as a brake.Similarly, the second torque-transmitting mechanism 260 is arrangedwithin the power flow between the second shaft 224 and the housing G ofthe transmission 200. Thus, similar to the first torque-transmittingmechanism 258, the second torque-transmitting mechanism 260 isconfigured to act as a brake. In this embodiment of the transmission 200therefore two of the five torque-transmitting mechanism are configuredto act as brakes and the other three torque-transmitting mechanisms areconfigured to act as clutches.

The third torque-transmitting mechanism 262 is arranged within the powerflow between the input shaft 202 and the sixth shaft 248. The fourthtorque-transmitting mechanism 264 is arranged within the power flowbetween the fourth shaft 236 and the sixth shaft 248. Moreover, thefifth torque-transmitting mechanism 266 is arranged within the powerflow between the fifth shaft 246 and the sixth shaft 248.

The kinematic couplings of the embodiment in FIG. 2 can further bedescribed with respect to the selective engagement of thetorque-transmitting mechanisms with respect to one or more components ofthe plurality of planetary gearsets. For example, in the transmission200, the first torque-transmitting mechanism 258 is selectivelyengageable to couple the first sun gear 214, the second sun gear 228,and the first shaft 222 to the housing G of the transmission 200. Thesecond torque-transmitting mechanism 260 is selectively engageable tocouple the first ring gear 216 and the second shaft 224 to the housing Gof the transmission 200. Moreover, the third torque-transmittingmechanism 262 is selectively engageable to couple the input shaft 202and the second carrier 232 to the sixth shaft 248 and fourth sun gear250. The fourth torque-transmitting mechanism 264 is selectivelyengageable to couple the second ring gear 230, the third sun gear 238,and the fourth shaft 236 to the fourth sun gear 250 and the sixth shaft248. Lastly, the fifth torque-transmitting mechanism 266 is selectivelyengageable to couple the third ring gear 240 and the fifth shaft 246 tothe fourth sun gear 250 and the sixth shaft 248.

Referring to FIG. 3, a different embodiment of a multiple speedtransmission 300 is shown. The transmission 300 includes an input shaft302 and an output shaft 304. The input shaft 302 and output shaft 304can be disposed along the same axis or centerline of the transmission300. In another aspect, the different shafts can be disposed alongdifferent axes or centerlines. In a further aspect, the different shaftscan be disposed parallel to one another, but along different axes orcenterlines. Other aspect can be appreciated by one skilled in the art.

The transmission 300 can also include a plurality of planetary gearsets.In the illustrated embodiment of FIG. 3, the transmission 300 includes afirst planetary gearset 306, a second planetary gearset 308, a thirdplanetary gearset 310, and a fourth planetary gearset 312. Eachplanetary gearset can be referred to as a simple or compound planetarygearset. For example, in some aspects, one or more of the plurality ofplanetary gearsets can be formed as an idler planetary gearset, althoughin FIG. 3 each planetary gearset is illustrated as a simple planetarygearset. One or more of the plurality of planetary gearsets can bearranged in different locations within the transmission 300, but forsake of simplicity and in this particular example only, the planetarygearsets are aligned in an axial direction consecutively in sequence(i.e., first, second, third, and fourth between the input and outputshafts).

The transmission 300 may also include a plurality of torque-transmittingor gearshifting mechanisms. For example, one or more of these mechanismscan include a clutch or brake. In one aspect, each of the plurality ofmechanisms is disposed within an outer housing of the transmission 300.In another aspect, however, one or more of the mechanisms may bedisposed outside of the housing. Each of the plurality of mechanisms canbe coupled to one or more of the plurality of planetary gearsets, whichwill be described further below.

In the embodiment of FIG. 3, the transmission 300 can include a firsttorque-transmitting mechanism 358 and a second torque-transmittingmechanism 360 that are configured to function as brakes (e.g., eachtorque-transmitting mechanism is fixedly coupled to the outer housing Gof the transmission 300). These brakes can be configured asshiftable-friction-locked disk brakes, shiftable friction-locked bandbrakes, shiftable form-locking claw or conical brakes, or any other typeof known brake. The transmission 300 can include a thirdtorque-transmitting mechanism 362, a fifth torque-transmitting mechanism364, and a fourth torque-transmitting mechanism 366 that are configuredto function as clutches. These can be shiftable friction-lockedmulti-disk clutches, shiftable form-locking claw or conical clutches,wet clutches, or any other known form of a clutch. With these fivetorque-transmitting mechanisms, selective shifting of at least eightforward gears and at least one reverse gear is possible.

The transmission 300 of FIG. 3 may also include up to eight differentshafts, which is inclusive of the input shaft 302 and output shaft 304.Each of these shafts, designated as a first shaft 322, a second shaft324, a third shaft 326, a fourth shaft 336, a fifth shaft 346, and asixth shaft 348, are configured to be connected to one or more of theplurality of planetary gearsets or plurality of torque-transmittingmechanism between the input shaft 302 and output shaft 304.

In FIG. 3, the first planetary gearset 306 can include a first sun gear314, a first ring gear 316, and a first carrier member 318 thatrotatably supports a set of pinion gears 320. The second planetarygearset 308 can include a second sun gear 328, a second ring gear 330,and a second carrier member 332 that rotatably supports a set of piniongears 334. The third planetary gearset 310 can include a third sun gear338, a third ring gear 340, and a third carrier member 342 thatrotatably supports a set of pinion gears 344. The fourth planetarygearset 312 can include a fourth sun gear 350, a fourth ring gear 352,and a fourth carrier member 354 that rotatably supports a set of piniongears 356.

The transmission 300 is capable of transferring torque from the inputshaft 302 to the output shaft 304 in at least eight forward gears orratios and at least one reverse gear or ratio. Each of the forwardtorque ratios and the reverse torque ratios can be attained by theselective engagement of one or more of the torque-transmittingmechanisms (i.e., torque-transmitting mechanisms 358, 360, 362, 364, and366). Those skilled in the art will readily understand that a differentspeed ratio is associated with each torque ratio. Thus, at least eightforward speed ratios and at least one reverse speed ratio may beattained by transmission 300. An example of the gear ratios that may beobtained using the embodiments of the present disclosure are also shownin FIG. 4. Of course, other gear ratios are achievable depending on thegear diameter, gear tooth count and gear configuration selected.

As for the transmission 300, kinematic coupling of the first planetarygearset 306 is shown in FIG. 3. The first sun gear 314 is coupled to thefirst shaft 322 for common rotation therewith. The first ring gear 316is coupled to the second shaft 324 for common rotation therewith. Firstpinion gears 320 are configured to intermesh with the first sun gear 314and first ring gear 316. First carrier member 318 is coupled for commonrotation with the third shaft 326.

With respect to the second planetary gearset 308, the second sun gear328 is coupled to the first shaft 322 and first sun gear 314 for commonrotation therewith. The second ring gear 330 is coupled to the fourthshaft 336 for common rotation therewith. Second pinion gears 334 areconfigured to intermesh with the second sun gear 328 and second ringgear 330, and the second carrier member 332 is coupled for commonrotation with the input shaft 302.

The third sun gear 338 of the third planetary gearset 310 is coupled tothe fifth shaft 346. The third ring gear 340 is coupled to the sixthshaft 348 for common rotation therewith. Third pinion gears 344 areconfigured to intermesh with the third sun gear 338 and third ring gear340, and the third carrier member 342 is coupled for common rotationwith the third shaft 326. Thus, the third carrier member 342 is disposedin common rotation with the first carrier member 318 as well.

The kinematic relationship of the fourth planetary gearset 312 is suchthat the fourth sun gear 350 is coupled to the fifth shaft 346 forcommon rotation therewith. The fourth ring gear 352 is coupled to thethird shaft 326 for common rotation therewith, and thereby disposed incommon rotation with the first carrier member 318 and the third carriermember 342. The fourth pinions 356 are configured to intermesh with thefourth sun gear 350 and the fourth ring gear 352. The fourth carriermember 354 is coupled to the output shaft 304 for common rotationtherewith.

With regards to the kinematic coupling of the five torque-transmittingmechanisms to the previously described shafts, the multiple speedtransmission 300 of FIG. 3 provides that the first torque-transmittingmechanism 358 is arranged within the power flow between the first shaft322 and the housing G of the transmission 300. In this manner, the firsttorque-transmitting mechanism 358 is configured to act as a brake.Similarly, the second torque-transmitting mechanism 360 is arrangedwithin the power flow between the second shaft 324 and the housing G ofthe transmission 300. Thus, similar to the first torque-transmittingmechanism 358, the second torque-transmitting mechanism 360 isconfigured to act as a brake. In this embodiment of the transmission 300therefore two of the five torque-transmitting mechanism are configuredto act as brakes and the other three torque-transmitting mechanisms areconfigured to act as clutches.

The third torque-transmitting mechanism 362 is arranged within the powerflow between the input shaft 302 and the fifth shaft 346. The fifthtorque-transmitting mechanism 364 is arranged within the power flowbetween the fourth shaft 336 and the sixth shaft 348. Moreover, thefourth torque-transmitting mechanism 366 is arranged within the powerflow between the fourth shaft 336 and the fifth shaft 346.

The kinematic couplings of the embodiment in FIG. 3 can further bedescribed with respect to the selective engagement of thetorque-transmitting mechanisms with respect to one or more components ofthe plurality of planetary gearsets. For example, in the transmission300, the first torque-transmitting mechanism 358 is selectivelyengageable to couple the first sun gear 314, the second sun gear 328,and the first shaft 322 to the housing G of the transmission 300. Thesecond torque-transmitting mechanism 360 is selectively engageable tocouple the first ring gear 316 and the second shaft 324 to the housing Gof the transmission 300. Moreover, the third torque-transmittingmechanism 362 is selectively engageable to couple the input shaft 302and the second carrier 332 to the fifth shaft 346, the third sun gear338 and fourth sun gear 350. The fifth torque-transmitting mechanism 364is selectively engageable to couple the second ring gear 330 and fourthshaft 336 to the third ring gear 340 and sixth shaft 348. Lastly, thefourth torque-transmitting mechanism 366 is selectively engageable tocouple the second ring gear 330 and the fourth shaft 336 to the thirdsun gear 338, the fourth sun gear 350 and the fifth shaft 346.

As previously described, each of the aforementioned embodiments iscapable of transmitting torque from a respective input shaft to arespective output shaft in at least eight forward torque ratios and onereverse torque ratio. Referring to FIG. 4, one example of a truth tableis shown representing a state of engagement of various torquetransmitting mechanisms in each of the available forward and reversespeeds or gear ratios of the transmission illustrated in FIGS. 2 and 3.It is to be understood that FIG. 4 is only one example of any number oftruth tables possible for achieving at least eight forward ratios andone reverse ratio, and one skilled in the art is capable of configuringdiameters, gear tooth counts, and gear configurations to achieve otherratios.

In the example of FIG. 4, the reverse ratio (Rev) can be achieved by theselective engagement of the torque-transmitting mechanisms as set forthin the table. As shown, the first torque transmitting mechanism (C1),second torque-transmitting mechanism (C2), and fifth torque-transmittingmechanism (C5) are selectively engaged to establish the reverse ratio.Thus, in transmission 200 of FIG. 2, the selective engagement ofmechanisms 258, 260, and 266 can establish the reverse ratio, whereas inthe transmission 300 of FIG. 3 the selective engagement of mechanisms358, 360, and 364 can establish reverse.

In neutral (Neu), none of the torque-transmitting mechanisms carrytorque. One or more of the torque-transmitting mechanisms, however, maybe engaged in neutral but not carrying torque. For example, the firstand second torque-transmitting mechanisms can be engaged in neutral,thereby resulting in the fifth torque-transmitting mechanism beingdisengaged between a shift between the one reverse ratio and neutral.

A first forward ratio (shown as 1st) in the table of FIG. 4 is achievedby engaging the first and second brakes and one of the clutches. In FIG.2, for example, the first torque-transmitting mechanism 258, the secondtorque-transmitting mechanism 260, and the third torque-transmittingmechanism 262 are engaged. Thus, when transitioning between neutral andthe first forward range, the first and second torque-transmittingmechanisms may already be engaged, and the third torque-transmittingmechanism is selectively engaged.

In a second or subsequent forward ratio, indicated as 2nd in FIG. 4, thefirst torque-transmitting mechanism, the second torque-transmittingmechanism, and the fourth torque-transmitting mechanism are selectivelyengaged. Therefore, when transitioning between the first forward ratioand the second forward ratio, the third torque-transmitting mechanism isreleased and the fourth torque-transmitting mechanism is engaged.

In a third or subsequent forward ratio, indicated as 3rd forward ratioin FIG. 4, the second torque-transmitting mechanism, thirdtorque-transmitting mechanism, and fourth torque-transmitting mechanismare engaged. To transition from the second forward ratio to the thirdforward ratio, for example, the first torque-transmitting mechanism isreleased and the third torque-transmitting mechanism is engaged.

In a fourth or the next subsequent forward ratio, indicated as 4th inFIG. 4, the second torque-transmitting mechanism, fourthtorque-transmitting mechanism, and fifth torque-transmitting mechanismare engaged. Thus, to transition from the third forward ratio andupshift to the fourth forward ratio, the third torque-transmittingmechanism is released and the fifth torque-transmitting mechanism isengaged.

In a fifth or the next subsequent forward ratio, indicated as 5th inFIG. 4, the second torque-transmitting mechanism, thirdtorque-transmitting mechanism, and fifth torque-transmitting mechanismare engaged. Thus, to transition from the fourth forward ratio andupshift to the fifth forward ratio, the fourth torque-transmittingmechanism is released and the third torque-transmitting mechanism isengaged.

In a sixth or the next subsequent forward ratio, indicated as 6th inFIG. 4, the third torque-transmitting mechanism, fourthtorque-transmitting mechanism, and fifth torque-transmitting mechanismare engaged. Thus, to transition from the fifth forward ratio andupshift to the sixth forward ratio, the second torque-transmittingmechanism is released and the fourth torque-transmitting mechanism isengaged.

In a seventh or the next subsequent forward ratio, indicated as 7th inFIG. 4, the first torque-transmitting mechanism, thirdtorque-transmitting mechanism, and fifth torque-transmitting mechanismare engaged. Thus, to transition from the sixth forward ratio andupshift to the seventh forward ratio, the fourth torque-transmittingmechanism is released and the first torque-transmitting mechanism isengaged.

In an eighth or the next subsequent forward ratio, indicated as 8th inFIG. 4, the first torque-transmitting mechanism, fourthtorque-transmitting mechanism, and fifth torque-transmitting mechanismare engaged. Thus, to transition from the seventh forward ratio andupshift to the eighth forward ratio, the third torque-transmittingmechanism is released and the fourth torque-transmitting mechanism isengaged.

The present disclosure contemplates that downshifts follow the reversesequence of the corresponding upshift (as described above), and severalpower-on skip-shifts that are single-transition are possible (e.g. from1st to 3rd or 3rd to 1st).

While exemplary embodiments incorporating the principles of the presentdisclosure have been disclosed hereinabove, the present disclosure isnot limited to the disclosed embodiments. Instead, this application isintended to cover any variations, uses, or adaptations of the disclosureusing its general principles. Further, this application is intended tocover such departures from the present disclosure as come within knownor customary practice in the art to which this disclosure pertains andwhich fall within the limits of the appended claims.

The invention claimed is:
 1. A multiple speed transmission, comprising:an input member; an output member; first, second, third and fourthplanetary gearsets each having first, second and third members; aplurality of interconnecting members each connected between at least oneof the first, second, third, and fourth planetary gearsets and at leastanother of the first, second, third, and fourth planetary gearsets; afirst torque-transmitting mechanism selectively engageable tointerconnect the first member of the first planetary gearset with astationary member; a second torque-transmitting mechanism selectivelyengageable to interconnect the third member of the first planetarygearset with the stationary member; a third torque-transmittingmechanism selectively engageable to interconnect the second member ofthe second planetary gearset with the first member of the thirdplanetary gearset and the first member of the fourth planetary gearset;a fourth torque-transmitting mechanism selectively engageable tointerconnect the third member of the second planetary gearset and thethird member of the third planetary gearset; and a fifthtorque-transmitting mechanism selectively engageable to interconnect thethird member of the second planetary gearset with the first member ofthe third planetary gearset and the first member of the fourth planetarygearset; wherein the second member of the first planetary gearset iscontinuously connected to the second member of the third planetarygearset; wherein the torque transmitting mechanisms are selectivelyengageable in combinations of at least three to establish at least eightforward speed ratios and at least one reverse speed ratio between theinput member and the output member.
 2. The multiple speed transmissionof claim 1, wherein the input member is continuously interconnected withthe second member of the second planetary gearset and the output memberis continuously interconnected with the second member of the fourthplanetary gearset.
 3. The multiple speed transmission of claim 1,wherein the plurality of interconnecting members includes a firstinterconnecting member continuously interconnecting the first member ofthe first planetary gearset with the first member of the secondplanetary gearset.
 4. The multiple speed transmission of claim 1,wherein the plurality of interconnecting members includes a secondinterconnecting member directly connected to the third member of thefirst planetary gearset.
 5. The multiple speed transmission of claim 1,wherein the plurality of interconnecting members includes a thirdinterconnecting member continuously interconnecting the second member ofthe first planetary gearset with the second member of the thirdplanetary gearset and the third member of the fourth planetary gearset.6. The multiple speed transmission of claim 1, wherein the plurality ofinterconnecting members includes a fourth interconnecting memberdirectly connected to the third member of the second planetary gearset.7. The multiple speed transmission of claim 1, wherein the plurality ofinterconnecting members includes a fifth interconnecting membercontinuously interconnecting the first member of the third planetarygearset with the first member of the fourth planetary gearset.
 8. Themultiple speed transmission of claim 1, wherein the plurality ofinterconnecting members includes a sixth interconnecting member directlyconnected to the third member of the third planetary gearset.
 9. Amultiple speed transmission, comprising: an input member; an outputmember; first, second, third and fourth planetary gearsets each having asun gear, a carrier member, and a ring gear, wherein the input memberand the output member are each interconnected to at least one of thefirst, second, third, and fourth planetary gearsets; a firsttorque-transmitting mechanism selectively engageable to interconnect thesun gear of the first planetary gearset with a stationary member; asecond torque-transmitting mechanism selectively engageable tointerconnect the ring gear of the first planetary gearset with thestationary member; a third torque-transmitting mechanism selectivelyengageable to interconnect the carrier member of the second planetarygearset with the sun gear of the third planetary gearset and the sungear of the fourth planetary gearset; a fourth torque-transmittingmechanism selectively engageable to interconnect the ring gear of thesecond planetary gearset with the ring gear of the third planetarygearset; and a fifth torque-transmitting mechanism selectivelyengageable to interconnect the ring gear of the second planetary gearsetwith the sun gear of the third planetary gearset and the sun gear of thefourth planetary gearset; wherein the torque transmitting mechanisms areselectively engageable in combinations of at least three to establish atleast eight forward speed ratios and at least one reverse speed ratiobetween the input member and the output member.
 10. The multiple speedtransmission of claim 9, wherein the input member is continuouslyinterconnected with the carrier member of the second planetary gearsetand the output member is continuously interconnected with the carriermember of the fourth planetary gearset.
 11. The multiple speedtransmission of claim 9, wherein the plurality of interconnectingmembers includes a first interconnecting member continuouslyinterconnecting the sun gear of the first planetary gearset with the sungear of the second planetary gearset.
 12. The multiple speedtransmission of claim 9, wherein the plurality of interconnectingmembers includes a second interconnecting member directly connected tothe ring gear of the first planetary gearset.
 13. The multiple speedtransmission of claim 9, wherein the plurality of interconnectingmembers includes a third interconnecting member continuouslyinterconnecting the carrier member of the first planetary gearset withthe carrier member of the third planetary gearset and the ring gear ofthe fourth planetary gearset.
 14. The multiple speed transmission ofclaim 9, wherein the plurality of interconnecting members includes afourth interconnecting member directly connected to the ring gear of thesecond planetary gearset.
 15. The multiple speed transmission of claim9, wherein the plurality of interconnecting members includes a fifthinterconnecting member continuously interconnecting the sun gear of thethird planetary gearset with the sun gear of the fourth planetarygearset.
 16. The multiple speed transmission of claim 9, wherein theplurality of interconnecting members includes a sixth interconnectingmember directly connected to the ring gear of the third planetarygearset.
 17. A multiple speed transmission, comprising: an input member;an output member; first, second, third and fourth planetary gearsetseach having a sun gear, a carrier member, and a ring gear, wherein theinput member and the output member are each interconnected to at leastone of the first, second, third, and fourth planetary gearsets; a firsttorque-transmitting mechanism selectively engageable to interconnect thesun gear of the first planetary gearset with a stationary member; asecond torque-transmitting mechanism selectively engageable tointerconnect the ring gear of the first planetary gearset with thestationary member; a third torque-transmitting mechanism selectivelyengageable to interconnect the carrier member of the second planetarygearset with the sun gear of the third planetary gearset and the sungear of the fourth planetary gearset; a fourth torque-transmittingmechanism selectively engageable to interconnect the ring gear of thesecond planetary gearset with the ring gear of the third planetarygearset; a fifth torque-transmitting mechanism selectively engageable tointerconnect the ring gear of the second planetary gearset with the sungear of the third planetary gearset and the sun gear of the fourthplanetary gearset; a first interconnecting member continuouslyinterconnecting the sun gear of the first planetary gearset with the sungear of the second planetary gearset; a second interconnecting memberdirectly connected to the ring gear of the first planetary gearset; athird interconnecting member continuously interconnecting the carriermember of the first planetary gearset with the carrier member of thethird planetary gearset and the ring gear of the fourth planetarygearset; a fourth interconnecting member directly connected to the ringgear of the second planetary gearset; a fifth interconnecting membercontinuously interconnecting the sun gear of the third planetary gearsetwith the sun gear of the fourth planetary gearset; and a sixthinterconnecting member directly connected to the ring gear of the thirdplanetary gearset; wherein the torque transmitting mechanisms areselectively engageable in combinations of at least three to establish atleast eight forward speed ratios and at least one reverse speed ratiobetween the input member and the output member.
 18. The multiple speedtransmission of claim 17, wherein the input member is continuouslyinterconnected with the carrier member of the second planetary gearsetand the output member is continuously interconnected with the carriermember of the fourth planetary gearset.